Implementing full home wifi with internet redundancy

I need to setup a network in a large 2 story house with a roof deck and i was wondering if this network infrastructure makes sense to some of the network experts that frequently view this forum. This is for a residential system which needs a fail safe way to ensure that the internet is always up and the computers within the network are always accessible remotely.

Here are the pieces I'm looking to buy to put together this network.:
Subscription to Cablemodem
Subscription to DSL

~$175 Linksys RV042 w/VPN, DYNDNS integration, and Dual Load Balancing WAN ports
~$75 Linksys WAP54G to provide main indoor wifi - set to a common ssid and channel
~$40 Linksys High Gain Antenna Kit to replace stock antenna on the WAP54G and provide extended range
~$375 Linksys WAP54GPE to provide outdoor/roof wifi - set to a common ssid and channel
~$85 2 Linksys WRE54G to provide coverage in dead spots for the indoor wifi - set to a common ssid and channel
~$25 Some PoE Injectors to send power to the outdoor access point
~$650 IPS-800 Remote Power Strip (wti.com)
~$$ Various 10/100 and Gigabit switches to provide ethernet connectivity through structured wiring.

Some of the problems i'm anticipating:
Will all of this wireless gear set to the same SSID and channel cause conflicts or collisions, or will work in perfect harmony?

I've installed WRE54G devices in 2 other places, and while they do provide more signal in netstumbler, it seems to lose packets and cause disconnections often. Has anyone used these things with any success?

Is the Linksys RV042 dyndns client smart enough to update the ip address if one of the ISP connections goes down?
I want to access the VPN by it's domain name even if one of the internet conenctions is down.

The idea with the remote power strip is to be able to reboot a component if it fails. For example, if the cablemodem fails, I want to be able to log in through the DSL and instruct the power strip to cycle power to the cablemodem. This assumes that 1 ISP connection is up, the DYNDNS entry gets updated with the dsl's ip address and that the VPN device itself has not crashed. If the VPN crashes we could provide a simple switch that will cycle power to the entire rack but this assumes someone is on site and available, which is not always the case. This paticular model has a ping mechanism that will cycle power on a port if it can no longer ping the device.

Is there a better way to do this?
We need full home wifi with internet redundancy and dyndns support.